Key takeaway

The Court of Appeal’s decision in Gluck v Endzweig [2026] EWCA Civ 145 confirms that an arbitration agreement may include bespoke correction or amendment powers, but those powers must still allow an award to become final and enforceable at a defined point. A clause allowing amendment “at any time” risks being severed, leaving the statutory correction regime under section 57 of the Arbitration Act 1996 to apply.

What happened in Gluck v Endzweig?

Mr Gluck sold a 50% shareholding in Net Pex Ltd to Evertop Ltd under a Share Purchase Agreement. A dispute arose over whether remaining instalments should be reduced under a price adjustment mechanism. The parties appointed two rabbis as arbitrators, constituting what they called a Beth Din, under a separate arbitration agreement.

That agreement granted the Beth Din authority “to amend and add to and change the judgment they have given, at any time.” Those three words, at any time, would prove to be the entire problem.

A partial First Award was issued in March 2024, confirming the Respondents were entitled to a price reduction. A Second Award followed on 28 May 2024, fixing the reduced sum. Shortly afterwards, Mrs Endzweig, the guarantor’s wife, and not herself a party to the arbitration, telephoned the Beth Din to raise concerns that the figures had failed to account for corporation tax. The Beth Din’s secretary emailed both parties to confirm that the relevant part of the award was being withheld pending a further ruling.

Mr Gluck, who had not been copied on any of this, then also contacted the Beth Din directly, without copying the Respondents, to assert that the Second Award was final and to request reasons. Both parties, in other words, were conducting private correspondence with the tribunal about the substance of the dispute.

Why did the first instance judge refuse enforcement under section 66?

Mr Gluck applied without notice to enforce the Second Award under section 66 of the Arbitration Act 1996. Permission was granted. The Respondents applied to set it aside, arguing the award was not yet final given the ongoing review.

The first instance judge agreed. He held that the Unlimited Amendment Clause was a valid expansion of the tribunal’s correction powers under section 57(1) of the Act, and that the statutory 28-day time limits could not be implied because they were inconsistent with the words “at any time.” He suggested, however, that the position was not permanent: if review requests became vexatious, the arbitrators could simply declare themselves functus officio.

It was a reasonable attempt at a solution. The Court of Appeal identified its flaw: a tribunal empowered to amend its award “at any time” is equally empowered to reverse a declaration of functus officio made under that same power. The proposed escape route led straight back into the problem.

The Court of Appeal’s decision

Lord Justice Dingemans (with whom Lords Justices Phillips and Lewis agreed) addressed three issues.

On interpretation: the Court accepted that the parties clearly intended a valid arbitration agreement and that, where possible, all its terms should be given effect, but section 58(1) of the Act provides that an arbitral award is “final and binding,” and this does not permit parties to agree a process under which an award may never become final at all. Section 58 is designed to accommodate institutional review mechanisms, such as Article 34 of the ICC Rules, not to create an open-ended power of revision. An award that can always be altered is not, in any meaningful sense, an award.

Can section 57 correction powers be expanded without a time limit?

On section 57: even treating the clause as an agreed expansion of correction powers under section 57(1), any such expansion must still produce finality at a defined point. A clause with no time limit whatsoever cannot satisfy that requirement, and the default 28-day provisions could not be read in to rescue it.

On severance: the Unlimited Amendment Clause was repugnant to the arbitration agreement as a whole, whose evident purpose was the final resolution of disputes by the Beth Din. The clause was severed. The default rules in section 57 applied. No valid correction had been made within the statutory 28-day window. The Second Award was enforceable on its terms.

For parties considering how an award may ultimately be enforced, we recently considered enforcing arbitration awards with final charging orders, including the distinction between enforcement security and interim restraint.

Can parties contact arbitrators privately during arbitration?

The Court of Appeal did not need to address the private communications between each party and the Beth Din, so it did not. It is worth noting nonetheless.

Evidence was submitted that unilateral contact with the tribunal is accepted practice within this type of religious panel, and that context is relevant. But in arbitration more generally, private contact with an arbitrator on matters of substance is highly irregular and carries real risk: challenges to the arbitrator, challenges to the award on grounds of procedural irregularity, and, at the more serious end, the loss of an otherwise enforceable award. The safest course is almost always to copy in the other side.

What this means in practice

For those drafting arbitration agreements: bespoke correction or amendment provisions are permitted, but they must include a defined time limit. “At any time” will be severed. The 28-day default under section 57 will apply in its place. And if no valid correction is made within that window, the award stands - errors and all.

Clauses designed to accommodate religious courts or specialist tribunals require particular care. The Arbitration Act 2025 has updated the statutory framework, and any drafting that pre-dates those changes is worth reviewing. The parties in this case no doubt intended a workable arbitration agreement. What they produced, inadvertently, was a clause that made one impossible.

We have previously considered London arbitration and the finality of arbitration awards, including the importance of final and binding awards and the English courts’ restrained approach to intervention.

Barnes Law’s Arbitration team advises clients on arbitration clauses, arbitral procedure, award correction, enforcement and challenges to arbitration awards. For more information, please contact our Arbitration team to discuss how we can support you.

Written by Barnes Law Managing Partner Yulia Barnes.